Method of forming hinge joints



N. B. DOUGLASS. METHOD OF FORMING HINGE JOINTS.

APPLICATION FILED JAN.5| 1921.

Patented Feb. 14, 1922.

2 SHEETSSHEET Q Inventor B Napoleon B-Dougl I flttorneg N. B. DOUGLASS.

I I METHOD orvroammc HINGE JOINTS.

APPLICATION FILED JAN. 5. 92!. 1 ,406,727. PatentedFeb. 14, 1922.

2 SHEETS-SHEET 2- In Q/entor Myra/eon Bflauglass WfW fltzforney barrenran er err-ice;

NAPOLEON B. DOUGLASS, OF @AKLAND, GALIFORNLk METHOD O35 FOR-MING HIEGEJGINTS.

Application filed. January 5, 1921.

To all whom it may concern:

Be it known that l, NAroLnoN B. DOUG- I,A'ss,'a citizen of the UnitedStates, residing at Oakland, in the county of Alameda and State 01California, have invented new and v allow the legs and other parts tofold. The

construction oi the hinges used. for this purpose in the past has beenrather expensive, and the object of the present invention is to simplifythe construct-ion or these hinges and produce a satisfactory andinexpensive hinge joint.

in carrying out this object I so cut and shape the end of one tubularmember as to form ears thereon which ears are presset outwardly orspread apart sutliciently to allow the other tubular member to fitbetween, it being understood that both tubular members are of the samediameter. iVhile the construction is a simple one and may not appear atfirst glance to involve any problems it is pointed out that this tubularstock is readily susceptible to mutilation and tearing, and being roundit becomes a difficult matter to provide punches and dies with propercutting ecges. After long experimentation I have succeeded in producingthis type of hinge joint in such a way that the punches and dies do notmutilate or tear the stock and preserve their cutting edgesfoneonsiderable periods of time.

In the accompanying drawings Fig. 1 shows a side elevation of a hingejoint formed between tubular members such as the present invention isconcerned with,

Fig. 2 shows a side elevation of the same taken at right angles to theview shown in Fig. 1,

l 3 shows a side elevation of a similar hinge joint slightly modified sothat the hinge members are free to swing in either direction pastperpendicular position,

Fig. 4 shows one of the tubular members with longitudinal slots cuttherein and representing the first step in my method of producing thishinge,

Specification of Letters ZFatent. Pgatgnteti Feb. 14, 1922.

Serial Ho. 435,181.

i 1g. shows 111 a diagrammatlc manner a suitable term of punch and diefor forming these slots.

Fig. 6 shows a view of one of the tubular members withthe materialbetween two of the slots cut awa representing the'second step of mymethod,

Fig. 7 illustrates the same member with the n'aterial at the oppositeside also cut away,

1.. L .1 j 1 ustiares in a ciagiammatic way a sun le too for cuttingthis material bet -keen slots away,

9 shows a view of the tubular memher in its .liSllQd state, the earsbeing spread apart or omet sutiicientlv to receive the end or theadjacent tubular member between them,

Fig. 10 illustrates the suitable form of swedgi die tor pressing outthese cars.

ihe type of hinge under consideration will now be described in detail.It consists of tubular members A and E of the same diameter. has a pairof ears l u ihe memoer ii 10 tormed on its end and spread apart toreceive the end of the other tubular member betweer them. i hinge pin 11is then i n and in the tubular member P for connecting the partstogether. in Figs. 1 and 2 I show a shoulder 12 on the member A to serveas a step whereby to limit the swinging movement of the hinge members inone direction. in 3 the material at both sides is cut away so themembers are free to swing in either direction past center. M

The steps involved in the production of this hinge are as follows Firstthe member is placed upon a die 13 and tour longitudinal slots 15 arecut therein by means of a punch 16. These slots are cut one at a time,and hence no special types of tools are required. Thereafter thematerial between the slots at two sides is cut by placing the tubularmember upon a punch 17 cooperating with a die 18 "terior. By having thepunch act inside the material can be cut away 'i hout danger ofmutilating or tearing the it is desired to form the shoulder 1? at oneside then the material is cut away on a straight line slightly above thebottom of the slots. In the ease of the opposite side the material ispreferably cut away on an arcuate line. As a result of these operationsa tubular member is formed as shown in Fig. 7 having at its end a pair-of ears 10. It now becomes necessary to flatten these ears out and tospread them apart sufiiciently to allow the end of the other tubularmember to fit between. To facilitate the next step the member A ispreferably placed in an annealing oven and heated. Thereafter the saidmember is placed upon a swedging die such as is illustrated in Fig. 10and the ears are offset andflattened out one at a time. This completesthe method with the exception of shaping the ears and punching the holestherefor which may be done in any suitable manner.

A hinge such as is produced by the present invention costs about ten percent of the cost of prior hinges used for the same purpose. The toolsused are in no sense special or difficult to make and they preservetheir cutting edges for a considerable period of time. By following thesteps herein narrated there is no danger of splitting the tubes or ofmutilating them in any way.

Having thus described my invention what I claim and desire to secure byLetters Patent is 1. The method of forming a hinge joint between tubularmembers of the same diameter which consists in cutting longitudinalslots in one of said members, cutting away the material between theslots at two sides thereof, leaving two ears, and thereafter setting theears out to the extent required to receive the end of the other tubularmemher.

2. The method of forming a hinge joint between tubular members of thesame diam eter which consists in cutting four. longitudinal slots in theend of the tubular memher one at a time, removing two of the stripsbetween the slots leaving two others form ing ears at diametricallyopposite points and thereafter setting the ears out sufliciently toreceive the end of the other tubu- -lar member- 3. The method of forminga hinge joint between tubular members of the same diameter whichconsists in cutting longitudinal slots in one of said members, removingthe material between the slots at two sides thereof by means of a punchacting upon the inside of the tubular member, and thereafter flatteningand spreading the two remaining portions so as t receive the othertubular member between them.

a. The method of forming a hinge joint between tubular members of thesame diameter which consists in cutting longitudinal slots in oneof'said members, removing the material between the slots at two sidesthereof, leaving tw ears at diametrically opposite points, heating thetubular member and thereafter spreading the ears apart so as to receivethe other tubular member between them.

5. The method of forming a hinge joint between tubular members of thesame diameter which consists in first cutting longitudinal slots in theend of one of said members, removing the material between the slots attwo sides, leaving two ears at diametrically opposite points, andthereafter (jli'setting said ears by means of a swedging (1 1e.

NAPOLEON B. DOUGLASS.

